Along the proposed course of the Illinois Michigan Canal, their was an approximately 140 foot drop from Lake Michigan to LaSalle at the canal junction with the Illinois River. It was because of this drop that multiple locks were planned along the canal route. The eastern section of approximately 10 miles was called the Summit Division. It was several feet higher than the surface of Lake Michigan. Because of this, it was originally proposed that there be a deep cut in this region. This would allow the water of Lake Michigan to flow down the Chicago River into the canal. It was also proposed that there be 15 locks; the first in Lockport and the last in LaSalle.
However, because of financial difficulties, there was a change in the plans for the Summit Division. The deep cut proposal was replaced by the shallow cut. This saved a substantial amount of money. A lock was constructed at Bridgeport on the south branch of the Chicago River. 10 miles west, a second lock was constructed. This was called Jack’s Lock. From here, the canal descended to its originally planned level.
Because this was a shallow cut and it was above the level of the lake, alternative water sources were needed for water sources for the Summit Division. One source was a pumping station near the canal Chicago River junction. This was a steam engine with four cast iron cylinder pumps 54 inches in diameter and seven feet in length. This pump transferred water from the Chicago River into the canal. Other source was a feeder canal from the Little Calumet River to the canal. It roughly parallels the course of the Cal Sag Canal. It was built in 1851.
This then was the canal set up from 1848 to the 1860’s. &nav
However in the 1860’s. the proposal of the deep cut for the Summit Division was revived. This however was given as a solution of the sewage issue in the growing city of Chicago. It was felt that the deep cut would result in a reversal of the course of the Chicago River. Water and sewage would flow from Lake Michigan down the Chicago River and then down the canal and eventually into the Illinois River.
The city of Chicago obtained permission from the state for this project. The contractor for this project was Sanger, Steel and Company. The contract was awarded in 1865. The project took 6 to 7 years. The project required removal of rock 60 feet wide and 10 feet deep for 10 miles. The canal was operated during this excavation. The cost of the project was approximately 3 million dollars. This was financed by the city. Later, the state reimbursed Chicago. After completion of the project, the locks at
at Bridgeport and Jack’s locks were dismantled. The Calumet Feeder canal was closed. The pumping station was shut down.
This project was initially successful. However, it gradually became a failure. As a temporizing measure, the Bridgeport pumps were reactivated.
Ultimately a totally new canal was needed. This was the Sanitary and Ship Canal completed in 1900. It ran from Chicago to Lockport. In 1907, the Cal Sag Canal was constructed from the Calumet River to the Sanitary and Ship Canal. This cut the I and M Canal in half. This resulted in the closure of of the I and M between Chicago and Lockport.